Do Races Exist? A Genetic Perspective

by Brian on February 6, 2018 in Genetics,Philosophy

Do Races Exist? A Genetic Perspective

People are often taught that races are entirely made up. And while we would like to accept this view on ideological grounds of equality, the obvious differences in appearance always leave us feeling like something isn’t quite right with that answer.

Clearly some kind of difference exists. But what is it? And does it matter?

Species vs population

Geneticists make two relevant distinctions here: species and population. To put it in simple terms, a species is a kind of organism–e.g., cat, dog, human–and a population is a subgroup of a species.

There are no perfectly clean criteria for what separates one species from another. Things are messy at the margins. Generally speaking though, willingness and ability to interbreed is used as the dividing line.

Populations are subgroups of a species that while being the same species, nonetheless, have different average characteristics. Different populations come about when there has been some degree of reproductive isolation, but not so much that full speciation has occurred. What we think of as races today have more in common with population-level distinctions.

However, race and population are not wholly synonymous. For example, millions of Italians immigrated to America during the period between 1880-1920 known as The Great Arrival. Most people would consider them white now, but at the time they were not considered white. Italians had an ambiguous in-between status. What happened? Did their genetics change? Did we discover a previously unknown genetic basis for reclassifying them as whites? Of course not, the reclassification was an utterly arbitrary one.

On the other hand, what about humans and neanderthals? Clearly different species… right? Well… maybe not.

Archeologists have discovered mixed settlements of modern humans and neanderthals who appear to have interbred quite readily. Consequently, some scientists reclassify neanderthals as a widely divergent population of humans rather than a separate species. Speciation is thought to often be a messy fission-fusion process of this sort rather than a one-time clean break.

So to bring this back to modern humans. Are they willing and able to interbreed? Quite enthusiastically it would seem. The case for different species within what we now call humans is extremely weak.

Different populations, however, are a reality. Differences in gene frequencies exist and have real consequences. Sephardic Jews are at higher risk of certain genetic conditions. In Southern India anesthesiologists ask patients about caste before undergoing a medical procedure. This is not racial profiling or the remnants of an antiquated system. It has real medical consequences. Because of inbreeding among castes, those with Vysya ancestry have a higher genetic susceptibility to a muscle relaxant that can be fatal.

Behavioral genetics

Let’s clear up two issues about Behavioral Genetics from the outset. First, the field of Human Behavioral Genetics presumes a single human species with essentially the same cognitive capacities. To overgeneralize, it looks for a genetic basis for variations in personality, preferences, and shades of ability. It does not look for gross differences like “can or cannot use language,” because the answer is so obvious as to not require rigorous scientific investigation.

Secondly, it does not predict strict determinism in behavior–this is one of the most widely held misconceptions.

Rather, it’s a diathesis-stress model. You can think of it as having certain predispositions. Let’s take a hypothetical gene for alcoholism. To have this gene would not mean you are destined for alcoholism. You have free will, you can simply choose not to be an alcoholic. But, it might mean that when you are put under stress it’s easier for you to break down and resort to alcohol in order to cope. The implication is that you might have to work harder at resisting temptation than others. But if you had such a condition the last thing you would want to do is bury your head in the sand. Knowing about it is also not an absolution from responsibility, but an empowering piece of information that you can use to do something about it.

The question for behavioral genetics is, to what extent do frequencies of genes affecting behavior differ among populations?

The answer is less straightforward because traits are usually highly polygenic (i.e., affected by more than one gene, sometimes thousands) and it’s very difficult to tease out genetic factors from other factors. You might, for instance, do a gene study and find a high correlation between a gene associated with white skin and people being Christian. But it would be absurd to conclude that you had found a “Christian gene.”

However, should frequency differences in genes that affect behavior be found, they could not be dismissed on ideological grounds.

Let’s say, hypothetically, we find frequency differences in some of these genes, what then? Can we conclude that people have fundamental differences at the population level? Well… still no. You’ve still got two things against this view:

1) The flaw of averages–that certain genes exist at a higher frequency in some populations is no guarantee that any particular individual of that population actually carries those genes.

Imagine a scenario where the average blue person has IQ 110 and the average green person has IQ 100. Would blue people be justified in having “IQ prejudice” against green people? What are we to say about the individual blue person with IQ 90 who insults an individual green person with IQ 150 for being a “dumb greeny?”

2) Again, Behavioral Genetics does not predict that genes are destiny. Do you take responsibility for your potentially harmful predispositions and manage them well? What about your strong points?

There is no substitute for assessing character and ability of the individual.


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